Conjunctivitis, sometimes referred to as pink eye, is an infection or inflammation of the conjunctiva - the thin, protective membrane that covers the surface of the eyeball and inner surface of the eyelids. It can be caused by bacteria, viruses and other germs that are transmitted to the eye through contaminated hands, towels, and eye makeup or extended wear contacts. It can also result from exposure to irritants such as chemicals, smoke or dust; or by pollen and other allergens. It is not uncommon for conjunctivitis to accompany a cold or flu.
 

Bacterial or viral conjunctivitis is contagious and tends to be prevalent in daycare centers and schools. It can spread by direct person-to-person contact, in airborne droplets that are coughed or sneezed, or from sharing makeup, towels and washcloths. Its hallmark sign is redness in the white of the eye that may be accompanied by increased tearing and/or a discharge that is watery or thick with mucus and pus and causes the eyelids to stick together.
Although usually a minor problem that improves within two weeks, some types can develop into serious corneal inflammation and vision loss if not treated. If you wear contact lenses and suspect you have conjunctivitis, discontinue wearing your contacts until the condition clears; you may also need to replace your contact lenses to prevent recurrence.

Viral conjunctivitis